How big is the main SQL database containing nodes, ways and relations? I do not mean the planet file but the actual GIS database (PostGIS?) where the edits are saved to along with editing history etc. I know the munin.openstreetmap.org server stats site but I cant really get oriented there. I guess in the past the main db server was called ramoth but I am not sure if this is still the case. Looking at ramoth's SQL size stats the db seems to be about 6 TB in size as of today. Will anyone please confirm ramoth really is the main database server?

EDIT: It seems like ramoth is read-only mirror, the main server seems to be katla - however the its database size is the same of course.

My findings were correct - the main database for www.openstreetmap.org that holds users, nodes, ways, relations, editing history etc. is about 6 TB in size as of today (November 2016). The database master (read/write) is on katla and there are few mirrors (look at hardware.openstreetmap.org for details).